Method of drying and roasting grain.



No. 805,367. PATENTED NOV. 21, 1905.

' V. LAPP.

METHOD OF DRYING AND ROASTING GRAIN.

APPLIUATION FILED MAY 31. 1904.

M beas'ses .Zevezalar: M

-UNITED STATES PATENT oFFIoE.

VALENTIN LAPP, OF LEIPSIC, GERMANY. METHOD OF DR YING AND ROASTINGGRAIN.

To all whom it may concern:

Be it known that I, VALENTIN LAPP, a subject of the King of Saxony,residing at No. 2 Georgi-Ring, Leipsic, in the Kingdom of Saxony, in theGerman Empire, have invented certain new and useful Improvements inMethods of Drying and Roasting Grain, of which the following is aspecification.

In the specification of United States Letters Patent No. 690,592 wasdescribed a process according to which large quantities of germinatedand non-germinated cereals were treated upon a perforated'floor in anhermeticallyclosed chamber to the action of air-baths both above andbelow the floor.

As is known, germinated barley contains about forty-five per cent. ofwater, and by the said process the barley was sought to be deprived ofthis water within the space of six hours at a temperature not exceeding4:5 centigrade. 1

As the apparatus in which the process was carried out was constructed ofiron, and notwithstanding all precautions variations of temperatureoccurred, water of condensation was deposited on the walls of thechamber and ran down into the grain again. This formation of water ofcondensation is increased by the fact that hitherto in the treatment ofgrain, including malt and the like, the warm drying-air was always drawnin an upward direction through the chamber, so that the apparatus andthe water contained in the malt were first heated below and the waterbegan to evaporate from the bottom layers, and the steam had to be drawnby powerful ventilation through the Whole body of malt, and as this wasabout 1.50 meters in thickness the steam became more or less condensedon the surfaces of the cooler upper layers of the grain and trickledback in drops into the lower layers again. By this means the drying wasconsiderably retarded and the amount of heat and air employed was muchgreater than would otherwise be necessary for the drying process.

Although the aqueous vapor tends to rise, it is condensed as it risesthrough the upper part of the layer of grain, which is very-thick, and,as stated, falls back as drops of water. The present invention has forits object to obviate this disadvantage when employing the largechambers described in the said specification; and it consists in causingthe drying-air to be drawn from abovedownward through thelayer of maltinstead of from below upward as heretofore, and, furthermore, in theregulation of Specification of Letters Patent.

Application filed May 31, 1904. Serial No. 210,517.

Patented Nov. 21, 1905.

' the temperature of the chamber walls and floor.

The warm air is for this purpose preferably introduced at several pointsof the upper part of the chamber in order to insure its uniformdistribution and is drawn off at the lowest part of the apparatus. Bythis means not only are the condensation of the aqueous vapor and thedownward flow of the resulting drops of water prevented, but also thedownward current of air carries with it the particles of water adheringto the grain at the same time that it effects the evaporation of theother part of the moisture. Those advantages are of course also obtainedby vacuum-drying, as also in this case the aqueous particles, which havea tendency to descend through the layer of malt, are sucked off directlyfrom below instead of being, as at present, first evaporated and thendrawn up" ward through the layer of malt, as above described.

When the malt is so far dried that no water of condensation is formed onthe grain or on the walls of the chamber, it is immaterial, so far asthe drying is concerned, whether the air is introduced from abovedownward or from below upward.

In practically carrying out the complete process, however, the operationis performed in such manner that about two-thirds of the water iswithdrawn from above downward, and then the last third is withdrawn frombelow upward, the supply of the hot drying-air being then eifected frombelow. By this means the perforated floor is heated sooner and to agreater degree than the malt lying upon the same, so that this is, as itwere, carried upon heated iron hurdles, by which means, as is wellknown, an aromatic'malt is produced.

The drawing off of the aqueous vapors or the aqueous particles wouldrequire a large' vacuum-pump. This work can therefore be very welleffected by means of a mixing-condenser, the condensable vapors beingcondensed by contact with water that can be utilized in the other partof the brewing process, while the non-condensable vapors are drawn offin the known manner by means of a vacuum-pum p. When using amixingcondenser, the efiect is produced that the water is drawn offbelow in liquid form, and consequently it is not required to be firstevaporated. The water condensed on the walls of the drying-chamber runsdownward, and the aqueous particles adhering to the malt IIO and to theperforated bottom are drawn downward, where they are collected and ledaway without being converted into vapor. The formation of water ofcondensation must, however, also be prevented on the outer surface ofthe casing of the drying-chamber, as the casing, in particular when oflarge dimensions, cannot follow the variations of temperature to thesame extent as occurs in the interior on heating or cooling, inparticular as the outer air acts directly upon the casing.

The latter is therefore surrounded externally by means of cooling orheating pipes, and the whole is inclosed in an insulating brickworkcovering. The apparatus is consequently not influenced by externalconditions of temperature, and cold or heat can be applied to it fromthe outside, whereby the formation of water of condensation is preventedand the whole can be maintained at a constant temperature. Inconsequence hereof the apparatus is particularly suited for maltingpurposes.

The upper pipes, which closely surround the chamber, are utilized ascooling-pipes, the metal casing of the chamber being used fortransmitting the cold. The lower pipes being used as heating-pipes arepreferably heated by means of steam and prevent, in particular when thedesiccation of the grain commences,

the formation of water of condensation.

On the accompanying drawing is shown, by way of example, a verticalsection of an apparatus constructed according to the above-describedinvention. The chamber (6, which is shown in elevation with a portionbroken away, has a cylindrical form and is provided with the necessaryfittings. It stands upon supports 6 and is completely isolated from theouter air by brickwork c at the sides and by an insulating layer ofnon-conducting material d at the top. Between the brickwork 0 and thewall of the chamber are provided the cooling-pipes 0, while under thecylinder are arranged the heating-pipesf. The air-inlet pipe is shown atg and the outlet at it, the perforated bottom of the chamber beingindicated at '6.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. The method of drying and roasting grain, whichconsists in first introducing a heatedair supply into the grain fromabove and withdrawing it from below, and then reversing the direction ofthe heated-air current during the latter part of the operation.

2. The method of drying and roasting grain, which consists inintroducing the heated-air supply into the grain from above andwithdrawing it by suction from below during approximately the firsttwo-thirds of the operation, and then reversing the direction of theheated-air current during the latter one-third.

8. The method of drying and roasting grain, which consists in passing aheated-air current from above through the grain in a suitabledrying-chamber upon a metallic grid, and minimizing the condensation ofmoisture therein by regulating the temperature of the chamber-walls,then reversing the direction of the air-current and applying externalheat to the floor of the chamber during the latter part of theoperation.

4. The method of drying an 1 roasting grain, which consists in passing aheated-air current through the grain in asuitable chamber from above andwithdrawing it from below, then reversing the direction of theair-current during the latter portion of the operation, and minimizingthe condensation of moisture in the chamber and facilitating theroasting by regulating the temperature of the chamber walls and heatingthe floor thereof.

5. The method of drying and roasting grain, which consists inintroducing the heated-air supply into the grain from above andwithdrawing it by suction from below during approximately the firsttwo-thirds of the operation, then reversing the direction of theaircurrent during the latter one-third, and applying external heat tothe floor of the apparatus during the latter period.

6. The method of drying and roasting grain, which consists inintroducing the heated-air drawing it from below by suction during approximately the first two-thirds of the operation; then reversing thedirection of the aircurrent during the latter one-third, applyingexternal heat to the floor of the apparatus during the latter period tofacilitate the roasting, and regulating the temperature of the walls ofthe apparatus to minimizing the condensation of moisture therein.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

VALENTIN LAPP. Witnesses: ()TTo GUNSHER, FR. B. ()MHORN.

supply into the grain from above and with

